General household pests are insects that have the potential to cause nuisance or harm to person and property, such as the German cockroach, American cockroach, Smokey-Brown cockroach, Oriental cockroach, house fly, biting fly, filth fly, red imported fire ant (RIFA), odorous house ant, carpenter ant, pharaoh ant, Argentine ant, mosquito, tick, flea, sowbug, pillbug, centipede, spider, silverfish, scorpion and bed bug. The following are some examples of nuisance or harm to persons and property. Cockroaches and flies can appear in people's living environment at any place and at any time. They generally contaminate food and articles subjecting people to threats of bacteria and viruses. The continued proliferation of colonies of red imported fire ants, Solenopsis invicta, are becoming a serious problem in the United States. Fire ants are attracted to electrical circuits and can cause failures in transformers, cables, connectors and related electrical hardware. Fire ants also can sting persons or animals and generally cause a localized allergic reaction on the area of the skin punctured by their stinging. Some individuals suffer a severe allergic reaction that can lead to anaphylactic shock, which can be fatal if not treated promptly. Many of the general household pests are potentially dangerous since their bites or stings can similarly lead to allergic reaction.
Insecticidal compositions have commonly been used to control general household pests. Of primary concern in developing an insecticidal composition to control general household pests is the insecticide's ‘knockdown’ and ‘mortality’ characteristics. Knockdown refers to quick, short-term immobilization or death of the pest. Pests can recover from knockdown immobilization. Knockdown usually occurs within 10-30 minutes, but the timing is pest dependant. For example, knockdown for house flies can occur at up to 2 hours because of their tolerance for insecticides and recovery abilities. Mortality refers to death of the pest. An optimal insecticide composition would have knockdown and mortality rates at or near 100% for all general household pests. Current insecticidal compositions, for example, have red imported fire ant and German cockroach mortality rates approaching 100%, but their knockdown rates are only 80% or less for red imported fire ants and 40% or less for German cockroaches. Improved knockdown rates and for many pests improved mortality rates are desirable to ensure effective protection of persons and property from general household pests.